let F be Field; :: thesis: for S being SymSp of F
for a, b being Element of S st not a _|_ holds
ProJ (a,b,b) = 1_ F
let S be SymSp of F; :: thesis: for a, b being Element of S st not a _|_ holds
ProJ (a,b,b) = 1_ F
let a, b be Element of S; :: thesis: ( not a _|_ implies ProJ (a,b,b) = 1_ F )
A1: b - b = 0. S by RLVECT_1:5;
assume not a _|_ ; :: thesis: ProJ (a,b,b) = 1_ F
hence ProJ (a,b,b) = 1_ F by A1, Th1, Th21; :: thesis: verum